Takefumi Auchi is a prosecutor often called the "Rookie Killer" due to his tendency to defeat novice defense attorneys. He is notable for being the first opponent of Ryuuichi Naruhodou.

According to Auchi, he never lost a case during his first seven years as a prosecutor

Auchi met Naruhodou in a murder trial, with the latter as a lawyer fresh out of law school. Auchi would later cheekily remark that he taught Naruhodou everything he knew.